亚心型四爿藻在CCCP作用下的光生物产氢的代谢途径

Electron transport pathways of hydrogen photobiological production metabolism in CCCP-treated Tetraselmis subcordiformis

摘要:

以添加CCCP (羰基氰化物间氯苯腙, Carbonyl cyanide m-chlorophenylhydrazone)的海洋绿藻亚心型四爿藻光生物制氢为研究体系, 使用作用于光合系统不同位点的抑制剂研究该藻产氢过程不同时段的代谢途径。结果表明: 四爿藻光生物产氢前期电子主要来自PS II光解水以及胞内分解代谢, 电子经由光合电子传递链传递至氢酶产生氢气; 而后期释放的氢气则是通过不依赖光合电子传递链的发酵途径产生。产氢过程厌氧发酵代谢途径主要产物是乙酸、乙醇, 其中乙醇代谢途径和氢酶竞争NAD(P)H, 不利于氢气的积累。

Abstract:

The CCCP-treated marine microalga Tetraselmis subcordiformis could photo-produce hydrogen for sevaral days. Effect of photosynthetic inhibitors on hydrogen production helped to draw the network of hydrogen metabolism by CCCP-treated T. subcordiformis: at the beginning of hydrogen production, electrons provided to hydrogenase are mainly from photolysis and photofermentation via PS I and electron chain; thereafter, fermentative hydrogen production is considered as the most responsible for providing electrons to hydrogenase, which is independent of photosystem electron transfer chain. Fermentative metabolites assay indicated that light and DBMIB inhibited fermentative ethanol produc-tion that is the competitive pathway for the cellular reducing power, resulting in higher photo-hydrogen yield.